Trump was reacting to a tweet from Sessions on Friday in which his former attorney general criticized the president, asserting that his decision to recuse himself in the early stages of the investigation into Russian interference in the 2016 election was “required by law” and that he did his “duty” and that “you’re damn fortunate I did.”

Sessions, a former Alabama senator who left the Trump administration in late 2018, is running for his old seat and is facing a runoff for the Republican nomination against former Auburn University football coach Tommy Tuberville. Sessions has sought to embrace Trump in the race, despite the president’s repeated recriminations.

Trump, who has long criticized Sessions for a recusal that opened the door for the appointment of special counsel Robert Mueller, urged Alabamans to “not trust Jeff Sessions” in a tweet Friday, writing that he “let our Country down.”

Sessions countered by arguing that the investigation ultimately led to Trump’s exoneration.

The Mueller probe found no proof the Trump campaign conspired with Russia but left unresolved whether Trump’s actions and intent could be viewed as obstruction of justice. In any case, the probe consumed much of the first two years of the Trump’s presidency.

“Your personal feelings don’t dictate who Alabama picks as their senator, the people of Alabama do,” Sessions posted in his tweet on Friday.

“Recused yourself ON DAY ONE (you never told me of a problem), and ran for the hills,” Trump shot back on Saturday. “The dirty cops, & others, got caught by better & stronger people than you. Hopefully this slime will pay a big…price. You should drop out of the race.”